I have a problem with the opening of the files saved from mail attachments. Access to the mailbox via IMAP. After downloading the file to my hard drive, it is becoming less original 10-30Kb. The downloaded file is not open, because he damaged. Using another mail client (such as Microsoft Outlook Express 6), there are no such problems.
Have used program Portable Thunderbird 22.214.171.124 (English version) without additional settings, and plug-ins (as is). A program install on a portable USB hard drive.